4 Jun
2021
4 Jun
'21
3:47 p.m.
Dear List
I am trying to use latest Osmo-core suite (osmo:stp,hlr,msc,bsc,bts,mgw)
with limesdr mini but facing issue as soon power rampup starts.
is there any stable release which I can use with limesdr mini
--
Akib Sayyed
Matrix-Shell
akibsayyed(a)gmail.com
akibsayyed(a)matrixshell.com
Mob:- +91-966-514-2243
4 Jun
4 Jun
3:52 p.m.
Hi,
I am not aware of any issue with limesdr mini and master, but I didn't
test lately (last weeks) with any LimeSDR mini.
Please create a bug report in redmine explaining what's failing, the
versions you use (master, commit hash) and provide logs, pcap files, etc.
Regards,
Pau
--
- Pau Espin Pedrol <pespin(a)sysmocom.de> http://www.sysmocom.de/
=======================================================================
* sysmocom - systems for mobile communications GmbH
* Alt-Moabit 93
* 10559 Berlin, Germany
* Sitz / Registered office: Berlin, HRB 134158 B
* Geschaeftsfuehrer / Managing Director: Harald Welte
4:02 p.m.
hi
limesdr mini does not have a onboard-clock which is good (precise)
enough for gsm requirements.
there is no input which can easily be used with an external source like
a gpsdo.
thus there is no realistic way to reliably do gsm with the -mini, sorry.
limesdr-usb with external 10mhz gpsdo or lime-net micro should work.
i haven't done any specific tests with that hw lately.
kind regards
--
- Joachim Steiger <jsteiger(a)sysmocom.de> http://www.sysmocom.de/
=======================================================================
* sysmocom - systems for mobile communications GmbH
* Alt Moabit 93
* 10559 Berlin, Germany
* Sitz / Registered office: Berlin, HRB 134158 B
* Geschaeftsfuehrer / Managing Directors: Harald Welte
4:38 p.m.
On 04/06/2021 15:02, Joachim Steiger wrote:
hi
limesdr mini does not have a onboard-clock which is good (precise)
enough for gsm requirements.
there is no input which can easily be used with an external source like
a gpsdo.
thus there is no realistic way to reliably do gsm with the -mini, sorry.
External clock can be enabled with LimeSDR Mini, but requires moving
(soldering) a 0R link and then you always have to use external clock.
Daniel Estevez put together a nice write-up:
https://destevez.net/2019/11/using-an-external-reference-with-the-limesdr-m…
Supreeth Herle has also created an LMS API port of Kalibrate, that can
be used to calculate and update VCTCXO DAC value in EEPROM:
https://github.com/myriadrf/kalibrate-lms
This is obviously not as good as having a GPSDO or similar, but may help.
Andrew
4:53 p.m.
I think problem is not with clock
Cause i tuned to tx freq i see no signal
But when i comment ramp code from osmobts i do get signal.
On Fri, 4 Jun 2021, 8:14 pm Andrew Back, <andrew(a)carrierdetect.com> wrote:
On 04/06/2021 15:02, Joachim Steiger wrote:
hi
limesdr mini does not have a onboard-clock which is good (precise)
enough for gsm requirements.
there is no input which can easily be used with an external source like
a gpsdo.
thus there is no realistic way to reliably do gsm with the -mini, sorry.
External clock can be enabled with LimeSDR Mini, but requires moving
(soldering) a 0R link and then you always have to use external clock.
Daniel Estevez put together a nice write-up:
https://destevez.net/2019/11/using-an-external-reference-with-the-limesdr-m…
Supreeth Herle has also created an LMS API port of Kalibrate, that can
be used to calculate and update VCTCXO DAC value in EEPROM:
https://github.com/myriadrf/kalibrate-lms
This is obviously not as good as having a GPSDO or similar, but may help.
Andrew
9:15 p.m.
Hi Andrew,
On Fri, Jun 04, 2021 at 02:38:06PM +0000, Andrew Back wrote:
yes,that is possible. I tried that, too, some years ago. The bigger problem,
as far as I recall, are the extremely stringent clock jitter requirements
at this input. There's no on-board PLL anymore, but it was directly the
sampling clock of the ADC, right?
In any case, at least as I recall, I didn't manage to get a spec
compliant GSM signal out of the LineSDR-mini with that approach using
the clocks I had at my disposal at the time.
But in any case, that jitter / phase noise is mostly a conformance
related topic and the signal definitely would be good enough to be
properly decoded by commercial UE, particularly in a lab setup with
otherwise near ideal conditions.
Regards,
Harald
--
- Harald Welte <laforge(a)osmocom.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
limesdr mini
does not have a onboard-clock which is good (precise)
enough for gsm requirements.
there is no input which can easily be used with an external source like
a gpsdo.
thus there is no realistic way to reliably do gsm with the -mini, sorry.
External clock can be enabled with LimeSDR Mini, but requires moving
(soldering) a 0R link and then you always have to use external clock. 
10:14 p.m.
On 04/06/2021 09:53, Akib Sayyed wrote:
I think problem is not with clock
Cause i tuned to tx freq i see no signal
But when i comment ramp code from osmobts i do get signal.
Hi Akib, the lime-mini has low RF power output and it you have the
"wrong" settings for tx power or power reduction you may not see any RF
signal at all from the mini.
Rather than speculating on such things. you will probably get much
better results by following Pau's advice and posting at the very least,
your config files for the osmo-* daemons (especially osmo-bsc,
osmo-bts-trx and and osmo-trx-lms)
The log output from those program will also be very useful to anybody
who might help.
As an extra plus, If you can, capture the traffic beween these programs
with tcpdump and also attach this pcap. But not to this mailing list! Do
not attach files here! - better to create a ticket on osmocom.org, or if
for some reason that is problematic, make your configs pcap and logs
available some other way by hosting them someplace and posting links to
them here.
k.
6 Jun
6 Jun
12:51 p.m.
Hi Harald,
On 04/06/2021 20:15, Harald Welte wrote:
Hi Andrew,
On Fri, Jun 04, 2021 at 02:38:06PM +0000, Andrew Back wrote:
yes,that is possible. I tried that, too, some years ago. The bigger problem,
as far as I recall, are the extremely stringent clock jitter requirements
at this input. There's no on-board PLL anymore, but it was directly the
sampling clock of the ADC, right?
Yes, there is no phase detector and ideally the input should be a square
wave. There are some more details on the MyriadRF wiki:
https://wiki.myriadrf.org/LimeSDR-Mini_v1.2_hardware_description#Clock_Dist…
limesdr
mini does not have a onboard-clock which is good (precise)
enough for gsm requirements.
there is no input which can easily be used with an external source like
a gpsdo.
thus there is no realistic way to reliably do gsm with the -mini, sorry.
External clock can be enabled with LimeSDR Mini, but requires moving
(soldering) a 0R link and then you always have to use external clock. In any case, at least as I recall, I didn't manage
to get a spec
compliant GSM signal out of the LineSDR-mini with that approach using
the clocks I had at my disposal at the time.
But in any case, that jitter / phase noise is mostly a conformance
related topic and the signal definitely would be good enough to be
properly decoded by commercial UE, particularly in a lab setup with
otherwise near ideal conditions.
Sure, for best performance would recommend using the larger LimeSDR-USB
or a LimeNET Micro, as Joachim suggested. However, you can use an
external reference with LimeSDR Mini and this may provide some
performance improvement, but with caveats.
Regards,
Andrew
1077
days inactive
1079
days old
7 comments
6 participants
participants (6)
-
Akib Sayyed -
Andrew Back -
Harald Welte -
Joachim Steiger -
Keith -
Pau Espin Pedrol